1 files changed, 26 insertions, 12 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index e8fba92d7cd9..2be019136287 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -745,9 +745,16 @@ xfs_log_move_tail(xfs_mount_t	*mp,
 
 /*
  * Determine if we have a transaction that has gone to disk
- * that needs to be covered. Log activity needs to be idle (no AIL and
- * nothing in the iclogs). And, we need to be in the right state indicating
- * something has gone out.
+ * that needs to be covered. To begin the transition to the idle state
+ * firstly the log needs to be idle (no AIL and nothing in the iclogs).
+ * If we are then in a state where covering is needed, the caller is informed
+ * that dummy transactions are required to move the log into the idle state.
+ *
+ * Because this is called as part of the sync process, we should also indicate
+ * that dummy transactions should be issued in anything but the covered or
+ * idle states. This ensures that the log tail is accurately reflected in
+ * the log at the end of the sync, hence if a crash occurrs avoids replay
+ * of transactions where the metadata is already on disk.
  */
 int
 xfs_log_need_covered(xfs_mount_t *mp)
@@ -759,17 +766,24 @@ xfs_log_need_covered(xfs_mount_t *mp)
                 return 0;
 
         spin_lock(&log->l_icloglock);
-        if (((log->l_covered_state == XLOG_STATE_COVER_NEED) ||
-                (log->l_covered_state == XLOG_STATE_COVER_NEED2))
-                        && !xfs_trans_ail_tail(log->l_ailp)
-                        && xlog_iclogs_empty(log)) {
-                if (log->l_covered_state == XLOG_STATE_COVER_NEED)
-                        log->l_covered_state = XLOG_STATE_COVER_DONE;
-                else {
-                        ASSERT(log->l_covered_state == XLOG_STATE_COVER_NEED2);
-                        log->l_covered_state = XLOG_STATE_COVER_DONE2;
+        switch (log->l_covered_state) {
+        case XLOG_STATE_COVER_DONE:
+        case XLOG_STATE_COVER_DONE2:
+        case XLOG_STATE_COVER_IDLE:
+                break;
+        case XLOG_STATE_COVER_NEED:
+        case XLOG_STATE_COVER_NEED2:
+                if (!xfs_trans_ail_tail(log->l_ailp) &&
+                    xlog_iclogs_empty(log)) {
+                        if (log->l_covered_state == XLOG_STATE_COVER_NEED)
+                                log->l_covered_state = XLOG_STATE_COVER_DONE;
+                        else
+                                log->l_covered_state = XLOG_STATE_COVER_DONE2;
                 }
+                /* FALLTHRU */
+        default:
                 needed = 1;
+                break;
         }
         spin_unlock(&log->l_icloglock);
         return needed;